package com.icesoft.core.common.helper;

import java.lang.reflect.Field;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.aop.TargetSource;
import org.springframework.aop.framework.Advised;
import org.springframework.aop.framework.AdvisedSupport;
import org.springframework.aop.framework.AopProxy;
import org.springframework.aop.support.AopUtils;

public abstract class AopTargetUtils {
	private final static Logger logger = LoggerFactory.getLogger(AopTargetUtils.class);

	/**
	 * 获取 目标对象
	 * 
	 * @param proxy
	 *            代理对象
	 * @return
	 * @throws Exception
	 */
	public static Object getTarget(Object proxy) {
		if (proxy == null) {
			return null;
		}
		if (!AopUtils.isAopProxy(proxy)) {
			return proxy;
		}
		return getTarget(_getTarget(proxy));
	}

	private static Object _getTarget(Object proxy) {
		if (proxy instanceof Advised) {
			TargetSource targetSource = ((Advised) proxy).getTargetSource();
			try {
				logger.info("get target object from Advised#getTargetSource[" + proxy.getClass().getName() + "]");
				return targetSource == null ? null : targetSource.getTarget();
			} catch (Exception e) {
				logger.error("get target object from Advised#getTargetSource[" + proxy.getClass().getName() + "] error",
						e);
			}
		}
		if (AopUtils.isCglibProxy(proxy)) {
			try {
				return getCglibProxyTargetObject(proxy);
			} catch (Exception e) {
				logger.error("get target object from Cglib [" + proxy.getClass().getName() + "] error", e);
			}
		} else if (AopUtils.isJdkDynamicProxy(proxy)) {
			try {
				return getJdkDynamicProxyTargetObject(proxy);
			} catch (Exception e) {
				logger.error("get target object from Jdk [" + proxy.getClass().getName() + "] error", e);
			}
		}
		return null;
	}

	private static Object getCglibProxyTargetObject(Object proxy) throws Exception {
		Field h = proxy.getClass().getDeclaredField("CGLIB$CALLBACK_0");
		h.setAccessible(true);
		Object dynamicAdvisedInterceptor = h.get(proxy);
		Field advised = dynamicAdvisedInterceptor.getClass().getDeclaredField("advised");
		advised.setAccessible(true);
		Object target = ((AdvisedSupport) advised.get(dynamicAdvisedInterceptor)).getTargetSource().getTarget();
		logger.info("get target object [" + target.getClass().getName() + "] from Cglib reflect ,from proxy:"
				+ proxy.getClass().getName());
		return target;
	}

	private static Object getJdkDynamicProxyTargetObject(Object proxy) throws Exception {
		Field h = proxy.getClass().getSuperclass().getDeclaredField("h");
		h.setAccessible(true);
		AopProxy aopProxy = (AopProxy) h.get(proxy);
		Field advised = aopProxy.getClass().getDeclaredField("advised");
		advised.setAccessible(true);
		Object target = ((AdvisedSupport) advised.get(aopProxy)).getTargetSource().getTarget();
		logger.info("get target object [" + target.getClass().getName() + "] from Jdk reflect ,from proxy:"
				+ proxy.getClass().getName());
		return target;
	}
}
